![autodesk moldflow insight command prompt only autodesk moldflow insight command prompt only](https://i.ytimg.com/vi/2hsUi3W51SM/maxresdefault.jpg)
It is thought that the HR design engineers would not be willing to repeat the meshing.
![autodesk moldflow insight command prompt only autodesk moldflow insight command prompt only](https://images.slideplayer.com/14/4338644/slides/slide_16.jpg)
Second, whenever the dimensional parameters are changed, the mesh should be regenerated repeatedly. First of all, it is necessary to train the design engineers to let them learn the entire CAE process from three-dimensional drawing to simulation. However, there are several difficulties in calculating the pressure drops for design purpose using such programs. Given a flow rate, the pressure drop can be obtained by a numerical simulation, which can be conducted in many commercial CAE programs. The pressure drop is always an important matter of concern in HR both in the sequential and conventional gating methods.
![autodesk moldflow insight command prompt only autodesk moldflow insight command prompt only](https://help.autodesk.com/cloudhelp/2022/ENU/AutoCAD-DidYouKnow/images/GUID-DD25FBED-FE5A-4281-BCD6-37209F45B751.png)
In an HR design, it is desirable to maintain sufficient flow conductance with limited pressure. It is also proven that it can handle fairly complicated HRs. Especially, CAE has been utilized for cooling line design of injection molds. There are several CAE (computer aided engineering) packages, such as MoldFlow, Modex3D, and 3D Timon, which are commercially successful in industry and also widely accepted as research tools. It has been widely used for design of molds and products as well as for troubleshooting in the processes. In other processes, molding optimization is an important issue. Technologies and studies of numerical filling simulations for conventional injection molding process have matured. Thus, the runner diameter should not be bigger than required. Moreover, the temperature can be non-uniform and fluctuating for wider runners. The melt retained in the runner will degrade while the stagnant phases. The increased volume per se is the situation that should be avoided. The pressure drops linearly along with the diameter while the volume increases quadratically. The increased diameter adds volume to the runner. In the meantime, the increase of the diameter causes serious problems which negatively impacts the molding process. However, the length is very difficult to shorten since it is supposed to set by the delivery requirement. The diameter of the runner should be increased while the length should be shortened. To maintain the required pressure at the gate, the pressure drop through the runner should be suppressed. Injection molding of a micro-device requires a high pressure at the gate to drive the filling flow in the micro-cavity. The pressure drop is especially important in microsystem. The dimensions of the manifold and the nozzles should be optimally determined considering both the allowable pressure drop and the necessary flow rate. Second, the runner system has to deliver melt in an efficient as well as balanced fashion. The first one is to maintain the target temperature within a tolerable range. In an HRS design, there are two important functions that should be guaranteed. As a result, the design process should be quick as well as systematic. Rapid product cycle demands the lead time be shorter and shorter while the reliability of mold tooling is always important. The HRS allows higher productivity, easier quality control, and apparent resin cost saving. A hot runner system (HRS) is widely adopted in modern injection molding processes.